The flowers are usually collected in racemes or spike-shaped inflorescences, rarely single flowers (venus slipper, cattleya). The flowers are three-membered, with a double perianth. The sepals are the same, and of the three petals, the middle (morphologically upper) is very different from the others, forming a lip. The lip often has a long outgrowth back, filled with nectar — - a spur. Since the most convenient position for pollination is "lip down", in terrestrial orchids, the flower twists (resupination)during development. Epiphytic orchids with overhanging inflorescences do not require resupination. Almost from all known flowering plants, representatives of the family differ in the fusion of filaments of stamens, which can be one, two or very rarely three, with a column of ginecea in the so-called column, or gynostemia, — such a specific formation is found, in addition to orchids, only in representatives of the family . It is characterized by a significant reduction of androcea; the fusion of pollen grains in the